Grenade launcher for a gun with a gas cylinder



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LY I 1 4117001240- HTTURNEYs Sept. 24, 1957 .1 c. GARAND GRENADE LAUNCHER FdR A GUN WITH A GAS CYLINDER Filed March 24, 1954 J. c GARAND "Sept. 24, 1957 2,807,112

GRENADE LAUNCHER FOR A GUN WITH A GAS CYLINDER Filed March 24, 1954 2 Sheets-Sht 2 Arrarzzv's r:

nited States Patent ice 2,807,112 Patented Sept. 24, 1957 GRENADE LAUNCHER FOR A GUN WITH A GAS CYLINDER John C. Garand, Springfield, Mass., assignor to the United States of America as represented by the Secretary of the Army Application March 24, 1954, Serial No. 418,486

7 Claims. (Cl. 42-1) (Granted under Title 35, U. S. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.

This invention relates to devices for launching grenades and more particularly to a grenade launcher for gasoperated shoulder arms.

As is well-known, a grenade launcher is customarily a tube-like device releasably attached to the muzzle of a firearm so that a grenade, slidably mounted on the tube, is driven therefrom by the discharge of a blank cartridge. In conventional types of grenade launchers, the grenade receives the full impact of the exploded gases, therefore, a terrific recoil kick is given to the firearm. Consequently, when a grenade is launched, the stock of the firearm is generally rested on the ground and for convenience in firing the position of the firearm is reversed so that the trigger extends upwardly. Thus, considerable strain is placed on the angle of the stock at the pistol grip portion, which is its weakest point causing the stock to crack or break at that location.

Further, in prior art, the range of the grenade is governed by the degree of elevation at which it is launched and/or by the degree of engagement thereof on the launching tube. Thus, when the range is short, the elevation of the firearm is increased so thatthe grenade is lobbed to the target. It is obvious that this gives the enemy time to sight the grenade and move out of range. In those instances where range is adjusted by the degree of engagement of the grenade along the launching tube, the range is decreased by moving the grenade toward the front end of the tube. But, it is obvious that as the degree of engagement of the grenade on the launching tube decreases the accuracy with which the grenade is aimed becomes correspondingly decreased. Graduations are sometimes provided along the length. of the launching tube to indicate the position, therealong to which the grenade is to be mounted so as to be driven to various increments of range. It is well-known though that variation of small fractions of an inch in the mounting of the grenade on the tube makes a difference of several yards in the distance it is driven. It is also obvious that mounting the grenade exactly to the graduations takes time and care which is undesirable in military use. It is, therefore, an object of this invention to provide a device for launching a grenade from a gas-operated shoulder arm whereby the grenade is bottomed against the device for all increments of range and so always travels along the entire length of the launching tube.

It is another object of this invention to provide a device for launching a grenade from a gas-operated shoulder arm wherein the pressure of the gases acting on the grenade is regulatable.

It is a further object of this invention to provide a device for launching a grenade from a gas-operated shoulder arm wherein the exploded gases not required in launching the grenade are bled from the firearm so as to reduce recoil shock thereof. 1

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawings in which:

Fig. 1 is a fragmentary side view of the front end of a firearm with a grenade launcher attached thereto and a grenade mounted thereon;

Fig. 2 is an enlarged View along line 2+2 of Fig. 1;

Fig. 3 is an enlarged view along line 33 of Fig. 1 showing the gas escapement port in open position;

Fig. 4 is the same as Fig. 3 but showing the gas escape ment port in almost closed position;

Fig. 5 is a perspective exploded view of the grenade launcher;

Fig. 6 is a partially sectioned side view of the front end of the rifle pointing in the opposite direction; and

Fig. 7 is an enlarged view along line 7-7 of Fig. 6.

Shown in the figures is a rifle having a barrel 12 with a gas cylinder 13 mounted thereto by means of a bracket 14, a flash suppressor 15 attached to the muzzle end of the barrel, a grenade launcher 16 mounted on the flash suppressor and a grenade 17 slidably installed on the grenade launcher. Flash suppressor 15 is comprised of a base portion 18, mounted by gas tight means to barrel 12, and a hollow cylindrical flash suppressor portion 19 the inside of which forms an extension of the bore of the barrel. Flash suppressor portion 19 is terminated forwardly by a conical section 29 and is provided with a plurality of longitudinal slots 21 arranged radially therethrough. The outside diameter of flash suppressor portion 19 is increased adjacent the rear ends of slots 21 to form annular supports 22. Rearward of supports 22 is an annular recess 23 arranged to communicate with slots 21 by arcuate depressions 77 and to form a rearwardly and outwardly inclining valve seat portion 24. Pivotally mounted to the underside of base 18 on a transverse pin 78 is a manually operated latch member 25 having a hook portion 26 which extends forwardly from the front side of base 18 and is arranged to be biased downwardlyto a latching position.

Extending rearwardly into bracket 14 is a longitudinal well 27 having a portion 28 of smaller diameter which extends rearwardly from an annular ledge 29. A gas port 31 provides communication between the bore of barrel 12 and portion 28 and another gas port 30 spaced forwardly from gas port 31 provides communication between such portion and gas cylinder 13. Provided in base 18, in longitudinal alignment with well 27, is a longitudinal recess 32 which is terminated at the front end by a wall 33 and at the rear end by a wall 34. Provided in rear wall 34 is a cylindrical aperture 35 which is of Similar diameter as the adjacent portionof well 27 and arranged to be aligned therewith. Arranged in the front wall 33 is a bore 36 which is aligned longitudinally with aperture 35 but is of smaller diameter. Mounted for slidable movement in recess 32 and well 27 is a cut-off valve 37 having an annular rib 38 which is engageable with the inside of front wall 33 and is spaced from the front end of such cut-off valve so that an engagement portion 39 formed by such annular rib is permitted to extend forwardly from bore 36 for engagement with grenade launcher 16 when mounted on flash suppressor 15. A valve portion 40, on the rear end of cut-off valve 37, is slidable in portion 28 and is arranged to block gas port 30 when engagement portion 39 is pressed inwardly by the installation of grenade launcher 16 on flash suppressor 15. The rear portion of valve portion 40 is also arranged to partially obstruct gas port 31 when cut-off valve 37 is pressed inwardly as thereby the pressure of thegases passing downwardly through gas port 31 act against such front portion to press valve portion 40 against the orifice of gas port 30 to assurea gas tight, scalp A coil s pringl41 is mounted on cut-01f valve 37 and is arranged to bear against ledge, 29 and rib 38 so as to bias the cut-off valve to forward position wherein gas port 30 is unblock'edwhen-grenadelauncher 16 is removed. If spring 41is, unable to m'ove cut-off valve 37 forwardly because ofjcarbon-deposits, the gases fro'm the first. cartridge discharged in regular fire act'on the rear end of valve portion 40 as they pass through gas port 31 todrive such cut-off .valve to forward unblock position.

Grenade launcher 16 is comprised of a tube 42 having a flange'portion 43 and a conical adjustment member 44 rotatable about the outside-of such flange portion: The bore of tube 42 has a forward reduced diameter' portion 45 arranged to snugly receive the front end of flash suppressor portion 19 adjacent'conicalsection 20 and a rear portion 46 arranged to snugly receive support portions 22. Thereby, grenade launcher 16 is adequately supa,so7,112

ported on flash'suppressor 15 with a minimum of surface engageable therebetween to become secured together by carbon'deposits produced during fire. The front side of flangeportion 43 slopes forwardly and inwardly from the annular periphery 47 of such flange portion to an annular shoulder 48. Provided in the rear end of flange portion engageable with valve seat portion 24 of flash suppressor 15 to form a valvular means for sealing the gases at the rear end of tube 42 when the gases from an exploded cartridge act rearwardly on the front end of such tube during the launching of grenade 17.

Provided around conical recess 49 is an annular groove 52 arranged to receive hook portion 26 and thereby secure grenade launcher 16 to flash suppressor 15. When hook portion 26 is received by groove 52, grenade launcher 16 is rotatable; until the hook portion is resiliently received by a mating longitudinal recess 53 whereby the grenade launcher is secured against further rotation. A segmental cut 54 is provided in the periphery of tube 42, adjaeent the front end, and mounted therein by dovetail means is an outwardly arching leaf spring 55 arranged to resiliently restrain grenade 17 on grenade launcher 16 prior to launching. j

Provided; in the rear end of adjustment member 44 is a cylindrical recess 66, which is arranged to receive flangeportion 43 so that the rear faces thereof are aligned, and an axial bore 56 which rotatably receives shoulder 48. Adjustment member 44 is rotatably secured on shoulder 48 by a ring lock member 57 having inwardly protruding ends 63 which are resiliently received in an annular groove 58 in such shoulder. A washer 59 is installed between lock 57 and adjustment member 44 to assist in rotatably securing the adjustment member to tube 42. The front portion of the periphery of adjust- .ment member 44 slopes inwardly and forwardly from a serrated portion 60 to front side 61, and extending rearwardly from such side is a pair of opposed recesses 62, having end walls 67 less than 90 apart, which form valve closure portions 65 therebetween. Recesses 62 are aligned with a pair of mating gase escapement ports 64, which extend through shoulder 48 to the bore of tube 42 adjacent recess 23, when the adjustment member is rotated to an open position. Whenadjustment member 44 is'rotated to a closed position, valve closure portions 65 progressively block off gas escapement ports 64 until such gas escapement ports are completely blocked.

Limited rotation of adjustment member 44 between the open and closed positions is provided by a longitudinal pin 75 in cylindrical recess 66 of adjustment member 44 whichis slidingly cooperable with a circumferentialcut 76 in periphery 47 'of flange portion 43.

jecting detent portion 70 arranged to, engageably cooper:

ate with a plurality of notches 71 in periphery 47 when adjustment member 44 is rotated between the open and closed positions. Notches 71 are predeterminedly spaced to regulate the forces of gases permitted to act against grenade 17, for launching thereof to predetermined increments ofrange by regulating thev openingof gas escapement ports 64 and so the amount of gases bled therethrough. A section, noted at 72, is removed from adjustment member 44 immediately in back ,of detent 70 to provide resilient movement thereof during cooperation with notches 71. Provided in rear face 50 of flange 43 is a reference mark- 73 alignable with a series of graduations 74 corresponding to notches 71 so that when detent 70 is engaged in one thereof the reference mark 73 indicates the increment of range for which grenade launcher 16 is adjusted. Notches 71 are calibrated for the ranges of grenade 17 when the firearm is inclined at a 45 angle, which is easy for the operator to determine without extra accessories. V

' Operation V When a grenade 17 is to be launched'from the firearm, grenade launcher 16 is installed on flash suppressor 15 as hereinbefore described with latch 25 securing such, grenade launcher in position. When grenade launcher 16 is fully installed, .cutofi valve 37 is pressed inwardly thereby blocking gas .port 30. Consequently, the gases from an exploded blank cartridge in barrel 12 are prevented-from entering gas cylinder 13 and are directed entirely out of the muzzle of the barrel into the bore of grenade launcher 16 to be directed either against grenade 17 or out of gas escapement ports 64 to the atmosphere., As the difference in the explosive force of separate cartridges is slight, theregulatable control of grenade launcher 16 is reasonably accurate so that the force directed; against the mounted grenade 17 is approximately the same in each setting of adjustment member 44. t The range of the target is then estimated by the opcrator andadjustment member 44 rotated, serrated portion facilitating the rotation, until reference mark 73 aligns with the one of the graduations 74 indicated for the estimated range. The engagement of detent 70 in the corresponding one of notches 71 indexes-and secures adjustment member 44. Themounting sleeveof grenade 17 is then fully installed on tube 42 and the rifie is inclined ata 45 angle towards the target for reasons hereinbefore' explained. The trigger is then actuated to fire the chambered blank cartridge. The exploded gases go farwardly' through the bore of barrel 12 and flash sup- .pressor 15-to act forwardly against grenade 17 and rearwardly against the front end of tube 42 to securely engage valve portion 51 thereon with valve seat portion 24 on flash suppressor 15, and thereby form a gas tight seal at the rear end of the tube while the grenade is being driven fromtthe tube, or rearwardly through depressions 77 to forceof the gases expelled through gas'escapement ports 64 is rather high, walls 67 are inclined so that adjustment member 44 will not be disturbed thereby.

Fromthe foregoing, it is.clearly apparent that there is here provided.for'gas-operated shoulder arms a rugged, easily manufactured grenade launcher having a high degree of accuracy, which reduces recoil shock to the firearm at the shorter ranges and which facilitates adjustments for increments of range.

Although a particular embodiment of the invention has been described in'detail herein, it is evident that many variations may be devised within the spirit and scope thereof and the following claims are intended to include suchvariations. r

I claim: Y

, 1'. Forafirearm having a barrel and a gascylinder mounted thereto by means of a bracket having gas ports therein for passing gases of an exploded cartridge from the barrel to the gas cylinder, a device for launching a grenade including valve means for blocking the gas ports, a flash suppressor mountable to the muzzle of the barrel, a tubular launching member attachable to said flash suppressor and adapted to receive the grenade thereon, said valve means being actuatable to a gas port blocking position by said launching member when attached to the firearm, said launching member being provided with gas escapement ports vented to the atmosphere, valvular means for blocking the escape of gases from the rear end of said launching member, said valvular means being actuatable by the gases while acting forwardly against the grenade and rearwardly against said launching memher, a conical adjustment member rotatably mounted on said launching member for blocking off said gas escapement ports, a series of graduations associated with said adjustment member to indicate the positions to which said adjustment member is to be rotated wherein the gases received by said grenade launcher are regulated for driving the grenade to predetermined increments of range, and detent means for indexing said adjustment member in accordance with said graduations.

2. In combination, a gas cylinder attached to a firearm barrel by a bracket having gas ports for the passage of gases of an exploded cartridge from the bore of said barrel to said gas cylinder and a well extending forwardly from said gas ports, a flash suppressor releasably attached to the muzzle of said barrel and comprising a base portion having a latch pivotally mounted thereto and a cylindrical valve member slidably mounted in said well for releasably blocking said gas ports, a slotted tubular flash suppressor portion extending from said base portion, said flash suppressor portion being provided with an annular shoulder portion of increased diameter and an annular recess forming an annular valve seat portion, a grenade launcher comprising a cylindrical member arranged to slidably receive the grenade thereon and having a bore for slidably receiving said flash suppressor portion, said bore having a portion to slidably receive said shoulder and a forward smaller diameter portion to slidably engage the front portion of said flash suppressor for support of said grenade launcher, a conical hollow flange on the rear end of said cylindrical member provided with gas escapement ports extending outwardly from said bore to the atmosphere and an annular groove cooperable with said latch for releasably securing said grenade launcher to said flash suppressor, said valve member being actuatable to block said ports when said grenade launcher is mounted on said flash suppressor, and an annular valve portion inside said flange engageable with said valve seat portion to seal the rear end of the bore during launching of the grenade, and an adjustment member rotatable around said tube, said adjustment member being cooperable with said gas escapement ports selectively regulating the escapement of gases from an exploded cartridges through said gas escapement ports and thereby drive said grenade to predetermined increments of range.

3. In a firearm having a barrel and a gas cylinder mounted to the underside thereof by means of a bracket, a longitudinal well in the bracket, a gas port to provide communication between the bore of the barrel and said well, a gas passage spaced forwardly from said gas port to provide communication between said Well and the gas cylinder, a flash suppressor having longitudinal slots mountable on the muzzle of the barrel, a grenade launcher slidably mounted on said flash suppressor and adapted to slidably receive a grenade, a valve slidably mounted in said well, said valve being movable 'by said grenade launcher to block said gas passage and partially obstruct said gas port when said grenade launcher is mounted on said flash suppressor, a valve portion on said grenade launcher engageable with a valve seat portion on said flash suppressor when the gasses received by said grenade launcher propel the grenade forwardly and said grenade launcher rearwardly, gas escapement ports in said grenade 6 launcher, calibrated means for adjusting thelpassage of gases through said gas escapement port, an annular recess in said flash suppressor having communication with said gas escapement ports, and arcuate depressions terminating said slots in said flashsuppressor to provide passage of gases from said slots to said recess.

4-. For a firearm having a barrel and a gas cylinder, a bracket for mounting the gas cylinder to the underside of the barrel, said bracket being provided with a longitudinal well, a gas port to provide communication between the bore of the barrel and said well and a gas p-assage spaced forwardly from said gas port providing com munication between said well and the gas cylinder, a flash suppressor mounted on the muzzle of the barrel, said flash suppressor being provided with radial slots and an annular recess having communication with the rear ends of said slots, a grenade launcher releasably mounted on said flash suppressor and arranged to slidably receive a grenade, a valve slidably mounted in said well, said valve being actuatable by said grenade launcher to block said gas passage and partially obstruct said gas port when said grenade launcher is mounted on said flash suppressor, valvular means for blocking the escape of gases from the rear end of the launching member during the launching of the grenade from said launching member, said grenade launcher being provided with gas escapement ports aligned with said recess, an adjustment member rotatably mounted on said grenade launcher for adjustably blocking ofisaid gas escapement ports, a series of graduations associated with said adjustment member for indicating the positions to which said adjustment member is to be rotated wherein the gases produced by an exploded cartridge in the barrel are regulated to drive the grenade to predetermined increments of range, and detent means for indexing said adjustment member in accordance with said graduations.

5. For a firearm having a barrel and an operating mechanism with a gas cylinder mounted to the barrel by a bracket and passages for passing gases from a cartridge fired from the barrel to the gas cylinder for actuating the operating mechanism, a launching member attachable to the muzzle of the barrel, a tube portion on said launching member for slidably mounting a grenade to the firearm and for directing the gases from the barrel against the grenade for the launching thereof, a valve member slidably mounted in the bracket for actuation by engagement of said launching member when mounted to the barrel from an open position to a closed position wherein the passages are blocked to prevent gases entering the gas cylinder to actuate the operating mechanism, an end portion on said valve member disposed in the path of the gases passing through the passages for actuation of said valve member by the gases to the open position when said launching member is detached from the barrel, radial gas escapement ports in the launching member for venting the gases received by said tube portion radially from the firearm, and adjustment means for selectively closing said gas escapement ports for regulating the force of the gases, appliable against the grenade to drive the grenade to predetermined increments of range.

6. For a firearm having a barrel and a gas cylinder mounted thereto by means of a bracket having passages therein for passing gases of an exploded cartridge from the barrel to the gas cylinder, a device for launching a grenade including a flash suppressor mounted to the muzzle of the barrel, a launching member attachable to said flash suppressor, a tube portion on said launching member adapted to slidably receive the grenade thereon and to direct gases from the barrel against the grenade for the launching thereof, a valve member .slidingly mounted in said bracket for blocking the passages by the engagement of said launching member when attached to said flash suppressor, radial gas escapement ports in said Y r a 7 t launching mamas; for vefitingtlie 'gases V is ly;there*rom-to the atmosphere, e erafipg va vubi fla h, i p e b a r ia u fi m' member actuatable 'to'block -the'escape "of the-gases from we rear end of said launching me'rhber Whensaidlaunching member is pressed rearwardly, an annular rim 'port rm t t r n p of sa mw P io r translating the pressure of the, gases received by said launching ir'nemb'er' to, rearward movement thereof; for actuating said Valvular means and adjustnientffiiearis cooperable with said gas escapementports to selectively "r'egnlate theescape of; gases thereto 'to the atmosphere and thereby the pressure of the gases acting against the grenade for driving the grenade 1t'o Pfedterhined'iiire m n s' la e; a a q a l '7. 'In a firearm haying a b'arreland a=gas cylinder mounted to the'unde'rside thereof'b'y means of a br'ackt,

a longitudinal warm the hra'c'kehag s port'to provide communication between the bore: of the" Barrel f'antl "said 7 wen, agaspassagesp'acedforwardly from saidgas pert and diametrically opp osed thereofto firoyide oihmdfib 'rnined increments of range. V

inerfiber'extending forwardly from said well forengaige rnent bysaid grenade launcher when f mounted on said flash suppressor for moving said valve member to the closed position, a valve portion on said valve' miember extending" rearwardly when said yalye rneinber is .in the clo'sedpdsition to block said passage' and under the inifluence of the'pressure' of the gases in said gas port for pressing said 'valve portion seal tight ag ainstthe mouth of said passage, ari'end portion on said yalyeportiondis'posed so'as to partially block said gas port when said. valve member is in the closed position to admit gas'esinto'said well from said gas port for moving saidfualveimember to "the open po sition when said; grenadefllauncheris"dis mounted from the firearm, valvular means'actuatable by the pressure ofthe gases received by said grenade launcher t for sealingjthe rear end of said'grenade launcher during launching of the'grenade, gas escape'ment ports in" said grenade launcher for venting the gases receivedjtherein radially to the atmospher e, and adjustment means 'for selectivelyregulating the gasesventedithroughsaidgas escapement ports for'lau'nching said grenadel tolpre'dete r- I References Cited in' the file Quins a en UNITED STATES PATENTS-F 2,094,305 Savani' I 2,453, 99 Coates 16 1948 2,564,684 Garand "Aug 

